\makeatletter
\renewenvironment{theindex}
       {\section*{\indexname}%
	\@mkboth{\MakeUppercase\indexname}%
		{\MakeUppercase\indexname}%
	\thispagestyle{plain}\parindent\z@
	\parskip\z@ \@plus .3\p@\relax
	\columnseprule \z@
	\columnsep 35\p@
	\let\item\@idxitem}
\makeatother